How to perform legal transactions in Interstate Business

Hi Everyone,

Learning the ropes in a quasi- hotshot truck. 24' bed, air-ride, 30,000 capacity. I have all the licensing/credentials I need for the state I'm out of (Washington State) for interstate. I work with brokers on a load board and have been making runs in Oregon. Some runs are Oregon to Oregon, others are OR/WA either way. I'm a couple loads in and realizing that I may need some licensing in OR.

I have no clue how these transactions work!

My thought process:
-I'm legal in WA, legal as interstate on INSURANCE/FMCSA/DOT/IFTA/IRP
-brokers pay me, but right now I'm sitting on ratecons from jobs
1.) Are the brokers technically the customer??
2.) Do I need a license in the state the broker is based in..?
3.) Or a license for transactions in the state I'm delivering to??
4.) Going to choose a factoring company for some invoices. Does that affect my questions above??

Man.. lots to learn, any skilled input would be great! Please don't guess though. haha

Thanks!